Tainted Obligation

Season 6 · Episode 4

When Thatcher returns to the hospital with a failed liver, Meredith must save his life; Izzie empathizes with a tumor-riddled patient; annoyed with Cristina's competitive zeal, Mark tricks her into assisting on an unusual surgery.

Invasion

Season 6 · Episode 5

The residents of Seattle Grace and Mercy West vie for their careers as the hospital merger begins; Arizona stands by enraged Callie when Callie's father employs a priest to help convince her to date men.

Invest in Love

Season 6 · Episode 8

The parents of Arizona's 10-year-old patient offer the hospital a generous donation, but Arizona finds herself in a conflict of interest when the patient's condition worsens; Cristina tests her boundaries with Owen.

New History

Season 6 · Episode 9

Owen recruits a fellow Iraq War veteran to be the new cardiothoracic surgeon, but Cristina questions the new surgeon's abilities; Izzie returns with her high school mentor seeking treatment for dementia.

Holidaze

Season 6 · Episode 10

As the holiday season passes, Miranda is visited by her father, who disapproves of her life choices; Mark and Lexie must cope with the arrival of a woman from his past; Thatcher questions the chief's recent behavior.

I Like You So Much Better When You're Naked

Season 6 · Episode 12

After learning about Richard's drinking problem, Derek confronts him; Izzie returns, hoping to reconcile with Alex; tensions run high for Teddy, Cristina and Owen in the aftermath of Cristina's startling confession.

How Insensitive

Season 6 · Episode 21

Bailey requires the team to have sensitivity training before admitting a 700-pound patient with numerous medical issues; Derek comes face-to-face with a former patient's husband in a wrongful death deposition.

Shiny Happy People

Season 6 · Episode 22

All reassess their personal lives after witnessing a chance reunion between two long-lost lovers in the emergency room; Karev treats a troubled teen (Demi Lovato); Meredith shares her suspicions with Cristina.